Red Hat Bugzilla – Bug 452360
Enabling European wireless channels makes iwl4965 behave erratically
Last modified: 2008-06-25 14:11:03 EDT
Description of problem:
Putting the line
options cfg80211 ieee80211_regdom=64
in /etc/modprobe.conf to enable channels 12 and 13 (used by some APs in Europe)
results in erratic behaviour from iwl4965. The system becomes very sluggish
every few seconds.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Ensure cfg80211 is loaded with ieee80211_regdom=64.
2. Reload iwl4965, iwlcore, mac80211 and cfg80211.
Very sluggish system, multiple ucode errors seen in dmesg (attached).
Euro channel access points detected and used.
Created attachment 309965 [details]
dmesg output with ieee80211_regdom=64 option.
Hmmm...well, I think there is some confusion here. The line in
/etc/modprobe.conf should either be
options mac80211 ieee80211_regdom=64
for older kernels or it should be
options cfg80211 ieee80211_regdom="JP"
for newer kernels. In either case, the dmesg output in comment 1 looks more
like a driver/firmware interaction problem to me. I would recommend changing 64
to "JP" and using a newer kernel:
Does this improve things for you?
OK, I didn't do *exactly* what you asked, I tried kernel-184.108.40.206-35.fc8 from
Koji and passed ieee80211_regdom="EU" (a guess, not wishing to upset the GPO
;)). This produced basically the same result from the desktop perspective:
sluggishness every few seconds. It also wouldn't associate. A dmesg is attached.
[Of course, if kernel-220.127.116.11-27.fc8 somehow contains newer code I'll gladly
try that version.]
Created attachment 310251 [details]
dmesg from kernel 18.104.22.168-35.fc8 using ieee80211_regdom="EU"
Note that this includes a stack dump from when I tried suspend/resume (see bug
John, re Comment #2: I've done a quick search on the IWL Bugzilla and nothing
concrete on this has turned up. Do you want me to try enabling ucode debugging
and report it to them?
Currently only rawhide kernels have support for "EU", so you probably want to
try "JP" for now. As for the ucode debugging, if you are willing to do that it
will probably be very helpful...thanks!
OK, you were right... I tried kernel-22.214.171.124-37.fc8 with ieee80211_regdom="JP"
and it appeared to behave. So I've no idea what EU was doing... closing as NOTABUG.